Hey Willard,
I'll pay and beta test a set of spings for an 044 if you need some test subjects, always wanted to try to have a spring conversion but between all the kids and work (and lack of skills and tools) never did start to. Didn't the 288xp have interchangable or were they just a mix of spring and rubber?
Same goes for a book about the Stihl '66', going from 064 to 066 660 and 661 with the history of development and changes and even IPL in the index and lots of pics, some experienced cutters here have a lot of knowledge that i think would be great to capture for the next generations.